The present invention relates to sheet protectors.
Sheet protectors are well known in the art and are commonly used as a protective covering for paper documents.
One well known type of sheet protector is manufactured by Avery Dennison Corporation of Pasadena, Calif. and is in the form of a pocket having an open top edge and closed side and bottom edges into which sheets of paper can be inserted through the open top edge. The sheet protector comprises a generally rectangular sheet of clear plastic material which is folded over on itself about a vertical fold line and welded closed on its bottom edge with a weld line and welded closed on the side opposite the fold line with a pair of spaced apart vertical weld lines. A strip of white plastic material is disposed in the area between the vertical weld lines. A plurality of holes are formed in the area between the vertical weld lines to enable the sheet protector and any documents held therewithin to be mounted on the rings of a binder without having to punch holes in the documents.
Although sheet protectors of the type described above are well known and widely used in commerce, one drawback of such a sheet protector is that paper documents can only be inserted into the protector through the open top edge. As a consequence, unless the paper documents are aligned perfectly along the open top edge, it is often difficult to slide the documents down and into the pocket of the sheet protector.
In U.S. Pat. No. 4,231,174 to Thompson there is disclosed a flat rectangular envelope having at least one wall which is transparent, the envelope in one form being fabricated from plastic film. Elongated mounting margins are formed along two side edges of the envelope, each having longitudinally spaced mounting apertures to enable the mounting of the envelope on a suitable support. The mounting apertures may be spaced to enable securing either edge of the envelope in a three-ring binder, or the envelope may be secured to other supports by means of ties. The mounting margins include some reinforcing means for improving the tear resistance of the mounting apertures. A plastic zipper is provided to close the top openable edge of the envelope. One wall may be formed from a magnetic material enabling the mounting of magnetic markers on the exterior of the transparent wall. The envelope may be secured to a rigid mounting board with coacting cords, which enable the envelope to be flip-flopped on the board without removal from the board.
In U.S. Pat. No. 4,516,871 to Leitman there is disclosed a sheet protector formed of upper and lower layers of substantially transparent plastic material. A pair of complementary tabs each laterally extending from the edges of the respective layers are integrally formed therewith. Heat sealing is utilized for securing together at least some of the peripheries of the layers as well as the matching tabs. An opening is provided to define in combination with the layers a receiving pocket whereby a sheet may be inserted in the pocket. A looseleaf type binder is provided for holding a plurality of the sheet protectors. The tab positions of the respective sheet protectors in the binder are sequentially indexed with respect to each other to provide a set of position selectable sheet protectors.
In U.S. Pat. No. 3,736,685 to Shibata there is disclosed an adhesive sheet material for mounting items in albums, scrapbooks and the like. The sheet material comprises an adhesive backing sheet and a transparent protective sheet. A suitable pattern of pressure sensitive adhesive films is printed on the backing sheet, leaving a certain amount of unprinted areas which are substantially lower than the printed portions.
In U.S. Pat. No. 3,670,434 to Shibata et al there is disclosed an adhesive sheet device for mounting photographs and other display items in albums, scrapbooks and the like. The device includes a relatively thick backing sheet and a relatively thin film of pressure-sensitive adhesive coating one surface of the backing sheet. A substantially uniplanar cover sheet of transparent material is disengageably adhered to the coated surface of the backing sheet for insertion of an item beneath the cover sheet for clear viewing of the item through the transparent cover sheet. The backing sheet is provided with means for eliminating the tendency of the sheet to buckle or warp when the cover sheet is repeatedly engaged with and disengaged from the backing sheet under pressure.
In U.S. Pat. No. 4,635,796 to Ozeki there is disclosed a film jacket for strip films comprising a surface sheet, a back sheet and a pair of locating means each consisting of at least two welded portions as a unit which are separated from each other in the width direction of the strip film at a distance slightly larger than the width of the strip film, said pair of the locating means being separated from each other in the length direction of the strip film pocket and said welded portions constituting a film pocket for holding a strip film therein. The welded portions of the paired locating means on either one of the upper and lower sides of the film pocket may be united together to form a short or long welded portion which is positioned between the welded portions on the other side of the film pocket.